Miami (CNN) — Inside a plane at Miami International Airport, baggage handlers are going on a shopping spree with passengers’ bags.

What they don’t know is that they are being recorded on a hidden camera. The Miami-Dade Police Department set up the camera as part of an ongoing police investigation into luggage thefts by the very airport workers who are supposed to get bags safely onto planes.

“It’s a problem we all face,” said police Lt. Pete Estis. “We will continue to be proactive until we can see that the claims of pilfering through luggage will actually decrease.”

And these insider thefts just don’t happen in Miami. A CNN analysis of passenger property loss claims filed with the TSA from 2010 to 2014 shows 30,621 claims of missing valuables, mostly packed in checked luggage. The rest occurred at security checkpoints. Total property loss claimed: $2.5 million.

John F. Kennedy International Airport in New York topped the list of airports with the most claims of thefts from luggage, followed by Los Angeles International, Orlando International and Miami International, according to the data.